Could Anorexia be Caused by Bacterial Infection?

Scientists have suggested that anorexia could be caused by bacteria that confuse the immune system, which leads to it attacking the brain to trigger feelings of personal disgust.

This is the first time anyone has linked an eating disorder with a physical infection. Traditional theories place the blame on social, psychological and environmental factors.

Experts from Morecambe Bay NHS Trust and Lancaster University also believe that Chronic Fatigue Syndrome (CFS) and Irritable Bowel Syndrome (IBS) have similar pathologies. They believe the notion of these disorders simply being the result of psychological problems or mental trauma ‘stretches credibility’.

Researchers on the study highlighted that women are much more susceptible to auto-immune disorders (e.g. pernicious anaemia), where the immune system attacks healthy cells. Similarly, women are around 10x more likely to suffer from anorexia, CFS and IBS. This suggests that the causes could be comparable.

Lancaster University’s Dr Quenton Wessels, said the diseases begin when the individual’s body comes into contact with a certain bacteria that produces an immune response that begins to accidentally attack healthy areas of the body. He said it’s a case of misidentification in that the body responds to something foreign by producing an antibody that’s meant to attack something else.

He went on to say it’s possible that auto-antibodies that act on the limbic system of the brain could encourage emotional extremes, for example fear or disgust. Dr Wessels said that these emotions are linked to the socially accepted ideals of what is or isn’t the perfect body size and shape. He said that then it’s only a small footstep for fear and disgust to be linked with obesity and food, both of which are in some cases demonised by the fashion world.

The researchers believe that specific bacteria are causing this response, profoundly suggesting that microbes within our bodies can have an effect on our mood.

About 750,000 people in the UK suffer from an eating disorder and approximately 75,000 of these suffer from anorexia. Around 7 million people in Britain suffer with IBS and 250,000 have been diagnosed with CFS, or ME.

According to previous studies, CFS and IBS could have a bacterial origin. IBS is commonly brought on following an episode of infectious diarrhoea, whereas CFS is sometimes triggered by viral hepatitis and infectious mononucleosis.

Dr Jim Morris, from the University Hospitals of Morecambe Bay NHS Trust, wrote alongside Dr Wessels and Dr Sue Broughton (University of Lancaster) in the Medical Hypotheses journal that the explanations currently offered for why anorexia occurs are not satisfactory. The team wrote that though psychological factors could hold some importance, as the primary cause they are unconvincing.

If this theory is proven, it opens up possibilities for medication and potential cures for disorders that have proven difficult to treat in the past. For example, blood transfusions could help to reverse the most severe anorexia cases.

Changing bacteria in the gut could also calm down symptoms of CFS and IBS.